1,721,102 research outputs found
Emerging technologies in solid drug delivery: An interview with Nadia Passerini
No full textNadia Passerini is interviewed by Hannah Makin, Commission Editor. Nadia Passerini is Associate Professor of Pharmaceutical Technology at the University of Bologna (Bologna, Italy). She obtained the degree in Pharmaceutical Chemistry and Technology at the University of Bologna in 1992 and the PhD in Pharmaceutical Science in 1997. Her research focuses on the study of drug delivery systems, developing new technologies and new apparatus for the production of solid dosage forms (microparticles, granules and tablets), which can optimize the bioavailability of drugs according to the specific needs of the therapy. Furthermore, she is interested in the solid-state characterization of the produced delivery systems in order to correlate their physicochemical properties to the in vitro release of the drugs. Currently, her research focuses in particular on the production and characterization of microparticles produced by the spray congealing technology. She is author of over 50 international peer-reviewed publications and over 50 contributions (poster and oral presentations) to national and international conferences
Spray congealing: A versatile technology for advanced drug-delivery systems
No full textSpray congealing is a low cost, simple and versatile method to produce microparticles without the use of organic or aqueous solvent. This review provides a detailed picture of the pharmaceutical applications of this technology, with an overview of the spray-congealed-based drug-delivery systems. First, the basic principles and equipment of spray congealing technology are presented. Then, representative examples of the drug-delivery systems are examined and critically discussed. Emphasis is given on the role of formulation variables, together with practical considerations for formulation design. In addition, the current status of the industrial applications of this technology within the pharmaceutical field is examined. The final part points out benefits, limitations and future perspectives of this technology in drug delivery
Hot air coating technique as a novel method to produce microparticles.
No full textIn this work a new technology to produce microparticles, as well as the equipment suitable for its application, are described. This technique, called hot air coating (HAC), was developed to overcome the drawbacks of the conventional spray-congealing technique and consists in a special venturimeter, deliberately designed to prevent any hindrance along the axial path through which the powder is conveyed. In HAC technique the raw material is a solid, generally small granules, which is aspirated through the “Venturi effect” and accelerated in a flux of hot air to soften and then to melt the excipient, especially on the particle surface. The microparticles then solidify during falling in air at room temperature. Model formulations, containing acetaminophen or theophylline as drugs and glycerilmonostearate, stearic acid or carnauba wax as coating waxes, were tested. The choice of the optimal operating parameters was found to be a function of the formulation and of the particle size of the starting material. A pressure of 3 atm and a temperature of 20°-60°C above the melting point of the excipient were found generally to be the optimal parameters for the coating process. The morphology, the in vitro dissolution profile and the possible drug/excipient interactions of formulations containing different percentages (30%, 50% and 70% w/w) of acetaminophen were evaluated. The results showed that the morphology and the dissolution profiles of the microparticles were quite different from those of the starting material; in particular the best coating was achieved by microparticles lower than 500 mm. Therefore, the HAC process could be a viable alternative to the conventional spray-congealing technique to produce microparticles with a high drug content
Spray congealed lipid microparticles for the local delivery of β-galactosidase to the small intestine
No full textOral local delivery of therapeutic biologics is generally limited due to the multiple obstacles of the gastrointestinal (GI) tract, mainly represented by acidic stomach pH and digestive enzymes. In the present study, spray congealing was used to prepare solid lipid microparticles (SLMs) loaded with β-galactosidase (lactase), an enzyme used for the treatment of lactose intolerance, to achieve a local drug delivery to the small intestine. Lactase was characterized in terms of activity at different pH, kinetic parameters and proteolytic degradation by digestive enzymes. Then, five lipid excipients were used to prepare unloaded SLMs, which were tested regarding lipase-induced digestion. The lipid with the best performance (glyceryl trimyristate) was used to prepare lactase-loaded SLMs. Spray congealed SLMs were spherical with very good encapsulation efficiency (>95%). The ability of the SLMs to protect the enzyme from the degradation in gastric environment was correlated with the particle size and the best formulation preserved the lactase activity up to 70%. Lactase was promptly released in simulated intestinal environment, and an in vitro positive food effect was observed. The present study demonstrated the potential of spray congealing for the preparation of solid lipid formulations able to achieve local oral delivery of a biologic drug
An investigation into the release behavior of solid lipid microparticles in different simulated gastrointestinal fluids
No full textIn recent years there has been a growing interest in solid lipid-based systems, particularly in solid lipid microparticles
(SLMs); however, only very few studies deeply investigated the dissolution behaviour of orally
delivered-SLMs. The present study provides new insights about the release performance in different gastrointestinal
fluids of SLMs containing a freely water soluble drug (caffeine, as BCS class I drug). Three different
formulations of SLMs were prepared by spray congealing using lipid excipients belonging to three chemical
classes: fatty acids, triglycerides and waxes. The dissolution profiles of caffeine were investigated using various
updated biorelevant dissolution media simulating the conditions of the gastrointestinal tract (gastric tract and
proximal human intestine). The profiles were statistically compared and the morphological changes of the
particles after dissolution were assessed by SEM analysis. The influence of the SLMs composition resulted to be
crucial on the dissolution behavior in the case of bigger particles (> 250 μm), while smaller SLMs (100-250 μm)
were mainly affected by the fluid composition. Moreover, regardless of the particle size, greater differences in
drug release profiles were noted by using different intestinal media compared to those obtained in gastric media.
In particular, the drug release from fatty acid and triglyceride-based SLMs was more controlled in the phosphate
buffer than in the intestinal biorelevant media; while the opposite behavior was noticed for waxy-bases SLMs.
Overall, the present study provides interesting insights which can be useful for the design of a multiparticulated
solid lipid formulation
Development of flexible and dispersible oral formulations containing praziquantel for potential schistosomiasis treatment of pre-school age children
No full textPraziquantel (PZQ), an anthelmintic drug used in developing countries for the treatment of schistosome infections, was processed using the fluid bed wet granulation technology to prepare fast dispersible granules, as an appropriate and flexible dosage form for pre-school-aged children. Granulation experiments were performed incorporating PZQ either in the powder mixture, according to the traditional way, or in the liquid phase containing wetting agents. In the powder mixture several excipients were tested: Flowlac 100 as filler, Galeniq 721 (isomalt) and Neosorb P 100 T (D-sorbitol) as sweeteners and PVP K30 as binder; while in the liquid phase Lutrol F68, Cremophor RH 40 or Tween 80 as surfactants were investigated. Different formulations loaded with 10% w/w (batches 1-8) and 20% w/w of PZQ (batches 9-13) were produced The majority of granules displayed good flow properties and uniform drug content. X-ray powder diffraction showed that PZQ remained in its original crystalline state, while differential scanning calorimetry and Fourier transform-infrared analysis evidenced the formation of chemical interactions among the ingredients. The solubilisation test performed in non-sink condition to reproduce the actual condition in which a child of 4 years takes the medicine revealed that granules quickly formed a very fine suspension in water (dV90 = 39.9 μm). Although after the granulation process the solubility of raw PZQ was not increased, adding the aqueous suspension to 500 ml of buffer solution of pH 1.5, simulating the fasted state of a child, 50% of the drug was dissolved after 30 min. After granule manipulation with milk and fruit juices, no PZQ degradation was observed during time. Finally, the selected granule formulation provided evidence to be stable even at hot and very humid climate (30°C/75% RH), at least for the examined time
New spray congealing atomizer for the microencapsulation of highly concentrated solid and liquid substances
No full textIncapsulation of azo- and xanthene-tattoo pigments in lipid microparticles colorant photo-stabilization and retention by the particle matrix in excised porcine skin
No full textNo abstract availabl
A novel approach for dry powder coating of pellets with Ethylcellulose. Part I: Evaluation of film formulation and process set up
No full textAn innovative dry powder coating technology was developed in a high-shear granulator using ethylcellulose (E10) as polymer. Several solid plasticizers were investigated with the aim of decreasing the polymer Tg at least to the highest possible working temperature (80°C). DSC analysis of physical mixtures of E10 and plasticizers evidenced that lauric acid (LA) was the most effective plasticizer. In order to reach the target temperature a liquid plasticizer, oleic acid (OA), was introduced in the coating formulation. Free films were then prepared and the target minimum film forming temperature (MFFT) was established in the range 70-80°C. Depending on the LA:OA weight ratio, Kollidon VA64 was included to decrease the LA recrystallization, while talc served as anti-sticking agent. Curing at the MFFT ensured the formation of homogeneous and stable films with good stability on storage. The dry powder coating process of placebo pellets was then developed, consisting of a combination of liquid assisted and thermal adhesion methods. The best coating formulations in terms of yields, coating efficiency (expressed as Relative Standard Deviation of the weight applied) and low pellets aggregation were based on E10:LA:OA in a weight ratio of 65:20:15 and 60:20:20. Moreover pellets remained stable after 1 year of storage (25°C/60% R.H.)
Exploring the use of spray congealing to produce solid dispersions with enhanced indomethacin bioavailability: In vitro characterization and in vivo study
No full textThe current study proposes an original oral delivery system for the bioavailability enhancement of indomethacin (IND), a BCS class II drug, with the aim to overcome the common limitations of amorphous solid dispersion. In fact, the potential risk of drug re-crystallization is a serious concern for the stability of amorphous systems and represents, despite the great bioavailability, one of the primary causes of their limited clinical applications. IND-loaded microparticles (MPs) were prepared by spray congealing using oral-approved excipients (Gelucire 50/13 and the recently marketed Gelucire 48/16). MPs were characterized regarding particle size, morphology, drug content and IND solid state; moreover, they were tested in vitro for IND solubility and dissolution rate. Solid state characterization indicated that IND was present into the MPs in the amorphous form. The best formulation showed a considerable enhancement in drug dissolution rate and 31-fold higher drug solubility than pure γ-IND. The oral administration of MPs showed 2.5-times increased bioavailability in vivo compared to either pure γ-IND or its physical mixture with unloaded MPs. Notably, the formulation was stable after 18 months with no changes in IND solid state and dissolution performance. This study offers a valid approach to enhance IND oral bioavailability by conversion into the amorphous form by spray congealed MPs, which have great potential for industrial application due to their characteristics of high encapsulation efficiency, no-toxicity, low-cost, prolonged stability and the use of a simple and easily scaled-up manufacturing technology
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